The taxonomy of the Ruppia genus is confused. This species can be extremely morphologically variable and respond to differing environmental conditions and therefore species identifications often link to differences in environmental conditions. Flower morphology and genetic studies are needed to evaluate the distribution limits of this species (Larkum et al. 2006). Ruppia cirrhosa is often misidentified as Ruppia maritima and is currently under taxonomic review.

Justification:
This is a hardy and abundant seagrass and has no known threats. Although there are some taxonomic issues due to problems with identification, because it is relatively widespread and fast to colonise and grow, it is listed as Least Concern.

In western Europe, this species occurs in brackish water sites, such as low-salinity ponds and mesohaline to polyhaline coastal lagoons. This species is rare in marine conditions. Abundance of this species can fluctuate considerably seasonally, and during severe winters it may disappear completely (Green and Short 2003). It is a fast growing species and colonises rapidly.